buy-hold-shell

A prediction market platform for Startup Shell. Members sign in with Google, receive a starting balance, and trade on outcomes of internal markets. Admins can create markets, manage user balances, and resolve outcomes.

Stack

• Next.js 16 — App Router, API routes, SSE for live market updates
• NextAuth v4 — Google OAuth
• better-sqlite3 — embedded SQLite database (stored in /data/market.db)
• Tailwind CSS v4

Setup

npm install

Create a .env.local:

NEXTAUTH_SECRET=...
NEXTAUTH_URL=http://localhost:3000
GOOGLE_CLIENT_ID=...
GOOGLE_CLIENT_SECRET=...
ADMIN_EMAIL=you@example.com   # grants admin privileges on sign-in

npm run dev

The database and schema are initialized automatically on first run. A seed market is inserted if the markets table is empty.

Features

• LMSR (logarithmic market scoring rule) automated market maker
• Real-time probability updates via server-sent events
• Probability history chart per market
• Leaderboard ranked by portfolio value
• Admin panel: open/close/resolve markets, deposit funds, view ledger